Method and apparatus for refining silicon using an electron beam
US7704478B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Jul 10, 2006 |
| Grant date | Apr 27, 2010 |
| Priority date | — |
| Expiry date | Jun 20, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B33/037
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method and apparatus for refining silicon which can remove impurity elements such as phosphorus and antimony as well as impurity elements such as boron and carbon using an electron beam in the same vacuum chamber are provided. Silicon is irradiated and melted with an electron beam in a low vacuum inside a vacuum vessel, a compound-forming substance such as H2O which reacts with boron or the like in the molten silicon and forms a vaporizable oxide is introduced into the vacuum chamber, and impurity elements such as boron having a low vapor pressure in a vacuum are evaporated from the molten silicon as part of the vaporizable compound. Silicon in the vacuum vessel is then irradiated with an electron beam in a high vacuum in the vacuum vessel, and impurity elements contained in the silicon having a high vapor pressure in a vacuum such as phosphorus are removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.